Magnetic iron oxide-carbon nanocomposites: Impacts of carbon coating on the As(V) adsorption and inductive heating responses

A novel magnetic nanocomposite of iron oxide nanoparticles encapsulated by carbon layer (Fe3O4@C) was prepared by using a two-step process of coprecipitation and hydrothermal method. The iron oxide nanoparticles with an average crystalline diameter of similar to 20 nm was used, whereas the concentration of C was varied from 1.25 to 10% by adjusting the mass ratio of glucose as a carbon source. We found that the arsenate removal efficiency of the Fe3O4@C nanocomposite increased with increasing C concentration, reached a maximum at 1.25% C concentration, and finally decreased for further increase in the C content. The adsorption kinetics process of the Fe3O4@C nanocomposite was well fitted with both Langmuir and pseudo-second-order kinetic models. In contrast, the heating efficiency of Fe3O4 nanoparticles was progressively reduced with increasing C content, regardless of the AC field value. Our study indicates the use of carbon as an encapsulator for iron oxide nanoparticles is very promising as an advanced absorbent for removal of environmental pollutants, such as arsenate As(V) while it is not ideal for magnetic hyperthermia based cancer therapy. (C) 2017 Elsevier B.V. All rights reserved.